1. Field of the Invention
The invention relates to a wind energy installation with a concentric gear and generator arrangement according to the preamble of the main claim.
2. Description of the Prior Art
Numerous different drive train arrangements are known for wind energy plants. In addition to gearless plants, most plants are built up from a combination of a gear and a generator. In wind energy plants, the gear and generator are conventionally arranged successively as individual components on a machine support. In the case of damage, this allows a simple replacement of these components, but the overall structure thereof is long and consequently heavy and cost intensive.
In EP 811 764 B1, the gear and generator are incorporated in directly succeeding manner in a common housing, the gear being a single-step planetary gear and the casing is placed directly on the tower. The gear and generator have roughly the same external diameter, and both components are arranged in directly succeeding manner which leads to a compact, lightweight construction. However, the disadvantage arises that it is no longer possible to replace the individual components on the tower head.
In the case of damage to these components, the complete installation must be lifted down from the tower head. In addition, the installation in a common housing requires an approximate identical external diameter of both components, which once again does not lead to an optimum generator design.
WO 01/94779 A1 discloses an arrangement having a directly operated generator on the side opposite to the rotor. As a result of the large generator, this concept is extremely unfavorable from the economic standpoint because it is noncompetitive from the weight and cost standpoints.
DK 173 530 B1 discloses a very elongated drive train structure in which the gear and generator are successively arranged with an intermediate shaft. Although this structure allows the replacement of components, it is very heavy and cost intensive in its implementation.
The problem of the invention is to provide a wind energy installation allowing a simple replacement of gear and generator, and which has a compact lightweight construction. Advantageous embodiments are given in the subclaims.